DESCRIPTION: This proposal is designed to develop activity-based interventions to prevent obesity in normal weight 6-11 year olds who are at high risk of becoming obese due to parental obesity. Families will be assigned to one of three groups of family-based interventions: increased activity, decreased access to sedentary behaviors that compete with being active, and educational control. After six months of intervention, families will be followed at 12 months and then annually to evaluate treatment outcome.